RomanCastevet wrote:
Hi,
when I press the space bar to preview an image it often happens that a red glitch appears for an instant. There is no difference in the type of photo displayed. This problem exists on Big Sur but it was also previously on Catalina. I recorded my screen to to extrapolate an image and show you what exactly happens. I already tried the different solutions you propose like entering in safe mode or resetting pram/nvram. You find also a screenshot of my macbook pro specs. Can you help me please. Thank you.
https://discussions.apple.com/content/attachment/1d3b3ff7-48c6-4a77-8445-6113a18edecc
https://discussions.apple.com/content/attachment/a1af88bc-2d6e-459f-a079-067b56b9dbcf
https://discussions.apple.com/content/attachment/892b979f-9a0c-46ea-8e14-9f859bfe255a
Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus
all known to cause issues on the macOS
If you are using an external monitor disconnect it to test.
To trouble shoot further you can:
—Try a SafeBoot https://support.apple.com/en-us/HT201262
Takes noticeable longer to get to the login screen, does a 5 minute disk repair before it fully boots up, and certain system caches get cleared and rebuilt, including dynamic loader cache, etc.
Login and test. Reboot as normal and test. Caches get rebuilt automatically.
In Safe mode third party system modifications and system accelerations are disabled, it removes malware, etc hampering smooth operation, however a reboot will put it back to normal mode.
This test will tell you if third party interference; extensions etc are not loaded in safe boot mode.
—Test issue in another user (or guest user) account https://support.apple.com/guide/mac-help/set-up-other-users-on-your-mac-mtusr001/mac
This will tell you if it a universal issue or isolated to your user/admin account.
